mirror of https://github.com/docker/docs.git
106 lines
3.9 KiB
Markdown
106 lines
3.9 KiB
Markdown
---
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page_title: Docker Swarm
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page_description: Swarm: a Docker-native clustering system
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page_keywords: docker, swarm, clustering
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---
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# Docker Swarm: a Docker-native clustering system
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Docker `swarm` helps you control a cluster of Docker hosts (known as nodes)
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and expose them as a single "virtual" host.
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The Docker `swarm` manager can be interacted with using the Docker API, which means
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any tool which can communicate with a Docker Daemon using that API, can control
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a Docker swarm transparently: dokku, fig, krane, flynn, deis, docker-ui, shipyard,
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drone.io, Jenkins... and of course the Docker client itself.
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Like the other Docker projects, `swarm` follows the "batteries included but removable"
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principle. It ships with a simple scheduling backend out of the box, and as initial
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development settles, an API will develop to enable pluggable backends. The goal is
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to provide a smooth out-of-box experience for simple use cases, and allow swapping
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in more powerful backends, like `Mesos`, for large scale production deployments.
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## Installation
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> **Note**: The only requirement for Swarm nodes is they all run the _same_ release
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> Docker daemon (version `1.4.0` and later), configured to listen to a `tcp`
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> port that the Swarm manager can access.
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Docker `swarm` is currently only available as a single go binary on Linux. Download
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it from [the latest release](https://github.com/docker/swarm/releases/latest) page
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on GitHub.
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For example:
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```
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$ wget -O swarm https://github.com/docker/swarm/releases/download/v0.1.0-rc1/swarm-Linux-x86_64
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# OR
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$ curl -SsL https://github.com/docker/swarm/releases/download/v0.1.0-rc1/swarm-Linux-x86_64 > swarm
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$ chmod 755 swarm
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$ sudo cp swarm /usr/local/bin
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```
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## Nodes setup
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Each swarm node will run a swarm node agent which will register the referenced
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Docker daemon, and will then monitor it, updating the discovery backend to its
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status.
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The following example uses the Docker Hub based `token` discovery service:
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```bash
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# create a cluster
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$ swarm create
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6856663cdefdec325839a4b7e1de38e8 # <- this is your unique <cluster_id>
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# For each of your nodes, start a swarm agent
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# the Docker daemon <node_ip> doesn't have to be public (eg. 192.168.0.X),
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# as long as the manager and the docker cli can reach it, it is fine.
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$ swarm join --addr=<node_ip:2375> --discovery token://<cluster_id>
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# start the manager on any machine or your laptop
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$ swarm manage -H tcp://<swarm_ip:swarm_port> --discovery token://<cluster_id>
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# use the regular docker cli
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$ docker -H tcp://<swarm_ip:swarm_port> info
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$ docker -H tcp://<swarm_ip:swarm_port> run ...
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$ docker -H tcp://<swarm_ip:swarm_port> ps
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$ docker -H tcp://<swarm_ip:swarm_port> logs ...
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...
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# list nodes in your cluster
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$ swarm list --discovery token://<cluster_id>
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<node_ip:2375>
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```
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> **Note**: In order for the Swarm manager to be able to communicate with the node agent on
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each node, they must listen to a common network interface. This can be achieved
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by starting with the `-H` flag (e.g. `-H tcp://0.0.0.0:2375`).
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## TLS
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Swarm supports TLS authentication between the CLI and Swarm but also between
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Swarm and the Docker nodes. _However_, all the Docker daemon certificates and client
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certificates **must** be signed using the same CA-certificate.
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In order to enable TLS for both client and server, the same command line options
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as Docker can be specified:
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`swarm manage --tlsverify --tlscacert=<CACERT> --tlscert=<CERT> --tlskey=<KEY> [...]`
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Please refer to the [Docker documentation](https://docs.docker.com/articles/https/)
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for more information on how to set up TLS authentication on Docker and generating
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the certificates.
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> **Note**: Swarm certificates must be generated with`extendedKeyUsage = clientAuth,serverAuth`.
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## Discovery services
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See the [Discovery service](../discovery) document for more information.
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## Advanced Scheduling
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See [filters](../scheduler/filter) and [strategies](../scheduler/strategy) to learn
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more about advanced scheduling.
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